CN118264005A

CN118264005A - Rotor, rotating electrical machine, and driving device

Info

Publication number: CN118264005A
Application number: CN202311055074.0A
Authority: CN
Inventors: 松田和敏
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2022-12-26
Filing date: 2023-08-21
Publication date: 2024-06-28
Also published as: JP2024092394A; DE102023122693A1; US20240213837A1

Abstract

The present invention provides a rotor rotatable about a central axis, comprising: a rotor core having a plurality of magnet holes and a flow path through which a refrigerant flows; and a plurality of magnets respectively accommodated in the plurality of magnet holes. The plurality of magnet holes and the flow path extend in the axial direction. The flow path is surrounded by a plurality of magnets as viewed in the axial direction. The plurality of magnets includes a first magnet and a second magnet. The plurality of magnet holes includes a first magnet hole that receives the first magnet and a second magnet hole that receives the second magnet. The first magnet is disposed radially outward of the second magnet. The shortest distance between the flow path and the first magnet is shorter than the shortest distance between the flow path and the second magnet as viewed in the axial direction.

Description

Rotor, rotating electrical machine, and driving device

Technical Field

The present invention relates to a rotor, a rotating electrical machine, and a driving device.

Background

A rotary electric machine is known in which permanent magnets are accommodated in through holes of a rotor. For example, patent document 1 discloses a rotor having a V-shaped magnet in which a pair of permanent magnets are arranged at a V-shaped opening angle toward the outer peripheral surface of the rotor, and an outer magnet arranged at a portion where the V-shaped magnet opens.

Prior art literature

Patent literature

Patent document 1: japanese patent No. 6331506

In the rotor described in patent document 1, the outside magnet is disposed radially outward of the V-shaped magnet, and therefore the magnetic flux passing through the outside magnet is larger than the magnetic flux passing through the V-shaped magnet. Therefore, when the rotor rotates, the amount of change in magnetic flux passing through the outer magnets is larger than the amount of change in magnetic flux passing through the V-shaped magnets. Thus, since the eddy current generated in the outer magnet is larger than the eddy current generated in the V-shaped magnet, the heat of joule heat generated in the outer magnet is larger than the heat of joule heat generated in the V-shaped magnet. Therefore, when the rotor rotates, the temperature of the outer magnet is higher than that of the V-shaped magnet, and therefore the outer magnet is liable to be demagnetized, and the output efficiency of the rotating electrical machine may be lowered.

Disclosure of Invention

In view of the above, an object of one embodiment of the present invention is to provide a rotor, a rotating electrical machine, and a driving device that can suppress a temperature rise of a first magnet.

One embodiment of the rotor according to the present invention is a rotor rotatable about a central axis, comprising: a rotor core having a plurality of magnet holes and a flow path through which a refrigerant flows; and a plurality of magnets respectively accommodated in the plurality of magnet holes. The plurality of magnet holes and the flow path extend in the axial direction. The flow path is surrounded by a plurality of the magnets as viewed in the axial direction. The plurality of magnets includes a first magnet and a second magnet. The plurality of magnet holes include a first magnet hole that receives the first magnet and a second magnet hole that receives the second magnet. The first magnet is disposed radially outward of the second magnet. The shortest distance between the flow path and the first magnet is shorter than the shortest distance between the flow path and the second magnet when viewed in the axial direction.

One embodiment of the rotating electrical machine of the present invention includes: the rotor; and a stator disposed radially outward of the rotor.

One embodiment of the driving device of the present invention includes: the rotating electrical machine; and a gear mechanism coupled to the rotor.

According to one aspect of the present invention, in the rotor, the rotating electrical machine, and the driving device, the temperature rise of the first magnet can be suppressed.

Drawings

Fig. 1 is a diagram schematically showing a driving device of a first embodiment.

Fig. 2 is a sectional view showing a rotor of the first embodiment.

Fig. 3 is a cross-sectional view showing a part of the rotor of the first embodiment.

Fig. 4 is a cross-sectional view showing a part of the rotor of the first embodiment, and is a partially enlarged view of fig. 3.

Fig. 5 is a cross-sectional view showing a part of a rotor according to a modification of the first embodiment.

Fig. 6 is a cross-sectional view showing a part of a rotor of the second embodiment.

Detailed Description

In the following description, a description will be given of a vertical direction based on a positional relationship when the driving device of the embodiment is mounted on a vehicle on a horizontal road surface. That is, the positional relationship with respect to the vertical direction described in the following embodiment may be satisfied when the driving device is mounted on a vehicle that is positioned on a horizontal road surface.

In each drawing, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The +Z side is the upper side in the vertical direction, and the-Z side is the lower side in the vertical direction. In the following description, the upper side in the vertical direction will be simply referred to as "upper side" or "axial side", and the lower side in the vertical direction will be simply referred to as "lower side". The X-axis direction is a direction orthogonal to the Z-axis direction, and is a front-rear direction of a vehicle in which the driving device is mounted. In the following embodiments, the +x side is the front side of the vehicle, and the-X side is the rear side of the vehicle. The Y-axis direction is a direction orthogonal to both the X-axis direction and the Z-axis direction, and is a left-right direction of the vehicle, that is, a vehicle width direction. In the following embodiments, the +y side is the left side of the vehicle, and the-Y side is the right side of the vehicle. In the following description, the left side of the vehicle is simply referred to as "left side", and the right side of the vehicle is simply referred to as "right side".

The positional relationship in the front-rear direction is not limited to the positional relationship in the following embodiment, and may be that +x side is the rear side of the vehicle and-X side is the front side of the vehicle. In this case, the +y side is the right side of the vehicle, and the-Y side is the left side of the vehicle. In the present specification, "parallel direction" includes a substantially parallel direction, and "orthogonal direction" includes a substantially orthogonal direction.

The central axis J shown in each figure is a virtual axis extending in the Y-axis direction, that is, the left-right direction of the vehicle. In the following description, unless otherwise specified, a direction parallel to the central axis J is simply referred to as an "axial direction", a radial direction centered on the central axis J is simply referred to as a "radial direction", and a circumferential direction centered on the central axis J, that is, a direction around the axis of the central axis J is simply referred to as a "circumferential direction".

The circumferential direction is shown by arrow θ in each figure. The side toward which the arrow θ faces in the circumferential direction (+θ side) is referred to as "circumferential side". The side opposite to the side toward which the arrow θ faces in the circumferential direction (- θ side) is referred to as "the circumferential direction other side". The circumferential side is a side which advances clockwise around the center axis J when viewed from the right side (-Y side). The other circumferential side is a side advancing counterclockwise about the center axis J when viewed from the right side.

In the following description, "radially outside" includes the following cases: when one direction is decomposed into a radially oriented component and a circumferentially oriented component, the radially oriented component is oriented radially outward. Likewise, "radially inner" also includes the following: when one direction is decomposed into a radial component and a circumferential component, the radial component is directed radially inward. In addition, "circumferential side" also includes the following cases: when one direction is decomposed into a component directed in the radial direction and a component directed in the circumferential direction, the component directed in the circumferential direction is directed to one side in the circumferential direction. Likewise, "circumferential other side" also includes the following cases: when one direction is decomposed into a radially oriented component and a circumferentially oriented component, the circumferentially oriented component is oriented to the other side in the circumferential direction.

< First embodiment >

The driving device 1 of the present embodiment shown in fig. 1 is a driving device that is mounted on a vehicle and rotates an axle 73. The vehicle to which the drive device 1 is mounted is a vehicle using a motor as a power source, such as a Hybrid Electric Vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an Electric Vehicle (EV). The driving device 1 includes a rotary electric machine 60, a gear mechanism 70 connected to the rotary electric machine 60, a case 63 accommodating the rotary electric machine 60 and the gear mechanism 70 therein, and a refrigerant flow path 90. In the present embodiment, the rotary electric machine 60 is a motor.

The casing 63 houses the rotating electric machine 60 and the gear mechanism 70 therein. The case 63 has: a motor case 63a that houses the rotating electric machine 60 therein; and a gear housing 63b that houses the gear mechanism 70 therein. The motor housing 63a is connected to the right side (-Y side) of the gear housing 63b. The motor housing 63a has a peripheral wall portion 63c, a partition wall 63d, and a cover portion 63e. The peripheral wall 63c and the partition wall 63d are, for example, part of the same single member. The cover 63e is formed separately from the peripheral wall 63c and the partition wall 63d, for example.

The peripheral wall 63c is cylindrical and surrounds the central axis J and opens rightward (-Y side). The peripheral wall 63c surrounds the rotating electrical machine 60 from the radially outer side. The partition wall 63d is connected to the left (+y side) end of the peripheral wall 63 c. The partition wall 63d partitions the inside of the motor housing 63a from the inside of the gear housing 63b in the axial direction. The partition wall 63d has a partition wall opening 63f that communicates the inside of the motor housing 63a with the inside of the gear housing 63 b. The bearing 64a is held by the partition wall 63 d. The cover 63e is fixed to the right end of the peripheral wall 63 c. The cover 63e closes the right opening of the peripheral wall 63 c. The bearing 64b is held by the cover 63e.

The gear case 63b accommodates the refrigerant O therein. Refrigerant O is stored in a lower region within gear housing 63 b. The refrigerant O circulates in the refrigerant flow path 90. In the present embodiment, the refrigerant O is lubricating oil that cools the rotating electrical machine 60 and lubricates the gear mechanism 70. For example, in order to exert a cooling function and a lubricating function, it is preferable to use an oil having a relatively low viscosity equivalent to the lubricating oil for an automatic transmission (ATF: automatic Transmission Fluid).

The gear mechanism 70 is connected to a rotor 10 of the rotary electric machine 60, which will be described later, and transmits rotation about a central axis J of the rotor 10 to an axle 73 of the vehicle. In the present embodiment, the gear mechanism 70 includes: a reduction gear 71 connected to the rotary electric machine 60; and a differential device 72 connected to the reduction gear 71. The differential device 72 has a ring gear 72a. The torque output from the rotating electrical machine 60 is transmitted to the ring gear 72a via the reduction gear 71. The lower end portion of the ring gear 72a is immersed in the refrigerant O stored in the gear housing 63 b. When the ring gear 72a rotates, the refrigerant O is stirred up, and the stirred up refrigerant O lubricates the reduction gear 71 and the differential gear 72.

The rotating electrical machine 60 includes: a rotor 10 rotatable about a central axis J; and a stator 61 facing the rotor 10 with a gap therebetween in the radial direction. In the present embodiment, the stator 61 is disposed radially outward of the rotor 10. The stator 61 is fixed to an inner peripheral surface of a peripheral wall portion 63c of the housing 63. The stator 61 has a stator core 61a and a coil assembly 61b mounted on the stator core 61 a.

The stator core 61a has a substantially annular shape centered on the central axis J. The stator core 61a surrounds a rotor core 30 of the rotor 10, which will be described later, from the radially outer side. The coil assembly 61b has a plurality of coils 61c mounted on the stator core 61 a. Although not shown, the coil assembly 61b may have a binding member or the like for binding the coils 61c, or may have a connection wire for connecting the coils 61c to each other.

Although not shown, the coil block 61b is electrically connected to an external power supply, not shown. When a current is supplied from an external power source to the coil assembly 61b, each of the plurality of coils 61c constitutes an electromagnet. At this time, joule heat is generated in each of the plurality of coils 61c, and the joule heat is transferred to the stator core 61a. Thereby, the temperature of the stator 61 including the stator core 61a increases.

As shown in fig. 2, the rotor 10 includes a shaft 20, a rotor core 30, a plurality of magnets 40, and a low thermal conductivity layer 80. As shown in fig. 1, the shaft 20 is cylindrical and extends in the axial direction about the central axis J. The shaft 20 is open at the left side (+y side) and the right side (-Y side). The left end of the shaft 20 protrudes into the gear housing 63 b. The shaft 20 is provided with a hole 20a connecting the inside of the shaft 20 and the outside of the shaft 20. The hole portions 20a are provided in plurality at intervals in the circumferential direction.

The rotor core 30 is fixed to the outer peripheral surface of the shaft 20. The rotor core 30 has a substantially annular shape centered on the central axis J. The rotor core 30 is made of a magnetic body. Although not shown, the rotor core 30 is formed by stacking a plurality of plate members in the axial direction. The plate member is, for example, an electromagnetic steel plate. As shown in fig. 2, the rotor core 30 includes a through hole 30a, a plurality of magnet holding portions 31, a plurality of rotor inner passages 34, and a plurality of rotor hole portions 35.

The through hole 30a is a hole penetrating the rotor core 30 in the axial direction. The through-hole 30a has a substantially circular shape centered on the central axis J, as viewed in the axial direction. The shaft 20 passes through the through hole 30a in the axial direction. The inner peripheral surface of the through hole 30a is fixed to the outer peripheral surface of the shaft 20.

The plurality of magnet holding portions 31 are provided at radially outer portions of the rotor core 30. The plurality of magnet holding portions 31 are arranged at equal intervals throughout the circumference in the circumferential direction. In the present embodiment, the magnet holding portions 31 are provided with eight. In the present embodiment, each magnet holding portion 31 is provided with one rotor inner passage 34 and three magnet holes 50.

A plurality of magnet holes 50 extend in the axial direction. In the present embodiment, each of the magnet holes 50 is a hole penetrating the rotor core 30 in the axial direction. Each of the magnet holes 50 may be a hole having a bottom at an axial end. In the present embodiment, the plurality of magnet holes 50 includes a first magnet hole 51 and second magnet holes 53, 54 provided radially inward of the first magnet hole 51. A first magnet hole 51 and a pair of second magnet holes 53, 54 are provided in each of the plurality of magnet holding portions 31.

The plurality of magnets 40 are housed in each of the plurality of magnet holes 50. In the present embodiment, each of the plurality of magnets 40 has a substantially rectangular parallelepiped shape extending in the axial direction. Each magnet 40 extends from, for example, an end on the left side (+y side) to an end on the right side (-Y side) of the rotor core 30. In the present embodiment, the magnet 40 is a permanent magnet. In the present embodiment, the magnet 40 is a neodymium magnet containing no heavy rare earth such as dysprosium or terbium. Therefore, the magnet 40 of the present embodiment has a lower demagnetizing temperature than the neodymium magnet containing heavy rare earth, but can reduce the material cost. Therefore, the manufacturing cost of the magnet 40 can be reduced.

As shown in fig. 3, the plurality of magnets 40 includes: a first magnet 41 accommodated in the first magnet hole 51; and a pair of second magnets 43, 44 respectively accommodated in the pair of second magnet holes 53, 54. Each magnet 40 is fixed in each magnet hole 50 by low thermal conductive layers 81, 83, 84 described later.

As shown in fig. 2, the rotor 10 includes a plurality of magnetic pole portions 10P. The plurality of magnetic pole portions 10P are arranged at equal intervals throughout the circumference in the circumferential direction. In the present embodiment, the magnetic pole portions 10P are provided with eight. Each of the plurality of magnetic pole portions 10P is composed of one magnet holding portion 31 of the rotor core 30 and a plurality of magnets 40 accommodated in magnet holes 50 provided in the one magnet holding portion 31. The plurality of magnetic pole portions 10P each have one first magnet hole 51, one pair of second magnet holes 53 and 54, one first magnet 41, and one pair of second magnets 43 and 44. The plurality of magnetic pole portions 10P include four magnetic pole portions 10N of the N-pole magnetic pole on the outer circumferential surface of the rotor core 30 and four magnetic pole portions 10S of the S-pole magnetic pole on the outer circumferential surface of the rotor core 30. The four magnetic pole portions 10N and the four magnetic pole portions 10S are alternately arranged in the circumferential direction.

As shown in fig. 4, in the magnetic pole portion 10P, the second magnet hole 53 and the second magnet hole 54 are arranged so as to sandwich the magnetic pole virtual line Ld in the circumferential direction. The magnetic pole virtual line Ld is a virtual line extending in the radial direction through the center of the magnetic pole portion 10P in the circumferential direction. The magnetic pole virtual lines Ld are provided in the respective magnetic pole portions 10P. The magnetic pole virtual line Ld passes through the d-axis of the rotor 10 as viewed in the axial direction. The direction in which the magnetic pole virtual line Ld extends is the d-axis direction of the rotor 10. The magnetic pole virtual line Ld passes through the center of the pair of second magnet holes 53, 54 in the circumferential direction between them. In the present embodiment, the center in the circumferential direction of the magnetic pole portion 10P is the center in the circumferential direction of the magnet holding portion 31.

The first magnet hole 51 is arranged radially outward of the pair of second magnet holes 53, 54. The first magnet hole 51 is disposed between the pair of second magnet holes 53, 54 in the circumferential direction. More specifically, the first magnet hole 51 is disposed between the radially outer end portions of the pair of second magnet holes 53 and 54. The first magnet hole 51 extends in a direction orthogonal to the magnetic pole virtual line Ld, as viewed in the axial direction. The magnetic pole virtual line Ld passes through the circumferential center of the first magnet hole 51. The first magnet hole 51 has a shape that is axially symmetrical with respect to the magnetic pole virtual line Ld, in a portion on one circumferential side (+θ side) and a portion on the other circumferential side (- θ side) with respect to the magnetic pole virtual line Ld.

The first magnet hole 51 has a magnet accommodating hole portion 51a and two outer hole portions 51b, 51c. The magnet accommodating hole 51a is rectangular in shape with a long side in the direction in which the first magnet hole 51 extends, as viewed in the axial direction. The magnet accommodating hole 51a is disposed radially outward of the rotor inner flow path 34. The magnet housing hole 51a has a first inner side surface 51e and a second inner side surface 51f. The first inner surface 51e is a surface facing radially inward of the inner surfaces of the magnet accommodating hole 51 a. The second inner surface 51f is a surface facing radially outward of the inner surfaces of the magnet accommodating hole 51 a.

The first magnet 41 is accommodated in the first magnet hole 51. More specifically, the first magnet 41 is accommodated in the magnet accommodating hole 51a. The first magnet 41 is disposed radially outward of the pair of second magnets 43, 44. The first magnet 41 is disposed radially outward of the rotor inner flow path 34. The first magnet 41 extends in a direction orthogonal to the magnetic pole virtual line Ld as viewed in the axial direction. The first magnet 41 is disposed at a position overlapping the magnetic pole virtual line Ld as viewed in the axial direction. The first magnet 41 has a first outer side 41a and a second outer side 41b. The first outer surface 41a is a surface facing radially outward, that is, a surface opposite to the rotor inner flow path 34 side, of the outer surfaces of the first magnets 41. The first outer side surface 41a is radially opposite to the first inner side surface 51 e. The second outer surface 41b is a surface facing the radially inner side, that is, the rotor inner flow path 34 side, of the outer surfaces of the first magnets 41. The second outer side surface 41b is radially opposite to the second inner side surface 51 f.

The outer hole 51b is connected to one end of the magnet accommodating hole 51a on one side (+θ side) in the circumferential direction. The outer hole 51c is connected to the other end (- θ side) of the magnet accommodating hole 51a in the circumferential direction. The outer hole portions 51b and 51c are, for example, hollow portions, and constitute magnetic flux shielding portions. The outer hole portions 51b and 51c may be filled with a nonmagnetic material such as a resin, or the nonmagnetic material may constitute the magnetic flux shielding portion. In the present specification, the "magnetic flux shielding portion" is a portion of the rotor core 30 that can suppress the passage of magnetic flux.

The pair of second magnet holes 53 and 54 are disposed radially inward of the first magnet hole 51. The pair of second magnet holes 53, 54 extend in a direction away from each other in the circumferential direction as seen in the axial direction from the radially inner side toward the radially outer side. The pair of second magnet holes 53, 54 are arranged in a V-shape that expands in the circumferential direction as they go radially outward, as viewed in the axial direction. The second magnet hole 53 is arranged on one circumferential side (+θ side) of the rotor inner flow path 34. The second magnet hole 54 is disposed on the other side (- θ side) in the circumferential direction of the rotor inner flow path 34. The second magnet hole 53 and the second magnet hole 54 are formed in a shape symmetrical to each other about a magnetic pole virtual line Ld as a symmetry axis when viewed in the axial direction.

The second magnet hole 53 has a magnet accommodating hole portion 53a, an inner hole portion 53b, and an outer hole portion 53c. The magnet accommodating hole 53a is rectangular in shape with a long side in the direction in which the second magnet hole 53 extends, as viewed in the axial direction. The magnet housing hole 53a is disposed on one side (+θ side) of the rotor inner flow path 34 in the circumferential direction. The magnet housing hole 53a has a first inner side surface 53e and a second inner side surface 53f. The first inner surface 53e is a surface facing the rotor inner flow path 34 side of the inner surfaces of the magnet accommodating hole 53 a. The second inner surface 53f is a surface facing the opposite side to the rotor inner flow path 34 side of the inner surfaces of the magnet accommodating hole 53 a. The inner hole 53b is connected to a radially inner end of the magnet accommodating hole 53a when viewed in the axial direction. The outer hole 53c is connected to an end portion of the magnet housing hole 53a radially outward as viewed in the axial direction. The inner hole portion 53b and the outer hole portion 53c constitute a magnetic flux shielding portion.

The second magnet hole 54 has a magnet receiving hole portion 54a, an inner hole portion 54b, and an outer hole portion 54c. The magnet accommodating hole 54a is rectangular in shape with a long side in the direction in which the second magnet hole 54 extends, as viewed in the axial direction. The magnet accommodating hole 54a is disposed on the other side (- θ side) in the circumferential direction of the rotor inner flow path 34. The magnet housing hole 54a has a first inner side surface 54e and a second inner side surface 54f. The first inner surface 54e is a surface facing the rotor inner flow path 34 side of the inner surfaces of the magnet accommodating hole portions 54 a. The second inner surface 54f is a surface facing the opposite side of the rotor inner flow path 34 side from the inner surface of the magnet accommodating hole 54 a. The inner hole 54b is connected to a radially inner end of the magnet accommodating hole 54a when viewed in the axial direction. The outer hole 54c is connected to an end portion of the magnet accommodating hole 54a radially outward as viewed in the axial direction. The inner hole 54b and the outer hole 54c constitute a magnetic flux shielding portion.

The pair of second magnets 43, 44 extend in a direction away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side. The pair of second magnets 43, 44 are arranged in a V-shape that expands in the circumferential direction as they go radially outward, as viewed in the axial direction. The second magnet 43 is disposed in the magnet accommodating hole 53 a. The second magnet 43 is disposed on one circumferential side (+θ side) of the rotor inner flow path 34. The second magnet 44 is disposed in the magnet accommodating hole 54 a. The second magnet 44 is disposed on the other side (- θ side) in the circumferential direction of the rotor inner flow path 34. As described above, the first magnet 41 is arranged radially outside the rotor inner flow path 34. As a result, the rotor inner flow path 34 is surrounded by the plurality of magnets 40 as viewed in the axial direction.

The second magnet 43 has a first outer side 43a and a second outer side 43b. The first outer surface 43a is a surface facing the opposite side of the rotor inner flow path 34 from the outer surface of the second magnet 43. The first outer side surface 43a is opposite to the first inner side surface 53 e. The second outer surface 43b is a surface facing the rotor inner flow path 34 side of the outer surfaces of the second magnets 43. The second outer side surface 43b is opposite to the second inner side surface 53 f.

The second magnet 44 has a first outer side 44a and a second outer side 44b. The first outer side surface 44a is a surface facing the opposite side from the rotor inner flow path 34 side, of the outer side surfaces of the second magnets 44. The first outer side 44a is opposite the first inner side 54 e. The second outer surface 44b is a surface facing the rotor inner flow path 34 side of the outer surfaces of the second magnets 44. The second outer side 44b is opposite the second inner side 54 f.

As shown in fig. 1, in the present embodiment, the plurality of rotor inner passages 34 are holes penetrating the rotor core 30 in the axial direction. The plurality of rotor inner passages 34 are passages through which the refrigerant O flows. A plurality of rotor inner flow passages 34 extend in the axial direction. The substantially central portions of the plurality of rotor flow passages 34 in the axial direction are connected to the plurality of holes 20a of the shaft 20 in the radial direction. As shown in fig. 2, in the present embodiment, eight rotor inner passages 34 are provided. The rotor inner passages 34 are provided at equal intervals over the entire circumference in the circumferential direction. Each of the rotor inner passages 34 is provided in each of the magnet holding portions 31.

In each magnet holding portion 31, the rotor inner flow passage 34 is arranged radially inward of the first magnet 41. The rotor inner flow path 34 is disposed between the pair of second magnets 43, 44 in the circumferential direction. As described above, the rotor inner passage 34 is surrounded by the single first magnet 41 and the pair of second magnets 43 and 44. Each of the rotor inner passages 34 constitutes a part of the refrigerant passage 90 through which the refrigerant O flows. The heat of the rotor core 30 and the heat of the plurality of magnets 40 are transferred to the refrigerant O flowing through the rotor inner flow path 34, and are released via the refrigerant O.

As shown in fig. 4, the in-rotor flow path 34 is arranged radially inward of a first virtual line Lc1, as viewed in the axial direction, the first virtual line Lc1 being orthogonal to the direction in which one of the second magnets 43 extends and passing through the center of the second magnet 43 in the direction in which the second magnet 43 extends. In the present invention, the radial direction inside of the first virtual line Lc1 means that, when the rotor core 30 is divided into two regions with the first virtual line Lc1 as a boundary, the radial direction inside of the two regions is arranged. The in-rotor flow path 34 is disposed radially inward of the second virtual line Lc2, and the second virtual line Lc2 is perpendicular to the direction in which the second magnet 44 extends and passes through the center of the second magnet 44 in the direction in which the second magnet 44 extends. In the present invention, the radially inner side of the second virtual line Lc2 means a radially inner region located in the two regions when the rotor core 30 is divided into the two regions with the second virtual line Lc2 as a boundary as viewed in the axial direction. Therefore, according to the present embodiment, the shortest distance between the rotor inner channel 34 and each of the first and second magnet holes 51, 53, 54 can be suppressed from becoming too short. Therefore, the thickness of the rotor core 30 between the rotor inner flow passage 34 and the first and second magnet holes 51, 53, 54 can be suppressed from becoming too thin, and therefore, the rigidity of the portion of the rotor core 30 surrounded by the plurality of magnets 40 can be suppressed from decreasing.

As shown in fig. 3, the in-rotor flow path 34 is provided at a position overlapping the magnetic pole virtual line Ld as viewed in the axial direction. In the present embodiment, the rotor inner flow passage 34 has a long hole shape extending in a direction perpendicular to the magnetic pole virtual line Ld, as viewed in the axial direction. In the present embodiment, the portion of the rotor inner flow path 34 on one circumferential side (+θ side) from the magnetic pole virtual line Ld and the portion of the rotor inner flow path 34 on the other circumferential side (- θ side) from the magnetic pole virtual line Ld are formed in a shape that is axisymmetric with respect to the magnetic pole virtual line Ld as a symmetry axis. The rotor inner flow path 34 has a circular arc shape protruding outward in the circumferential direction, as viewed in the axial direction. In the present embodiment, the circumferential outer side is a direction facing the opposite side to the direction facing the magnetic pole virtual line Ld side. Therefore, according to the present embodiment, compared to a case where the shape of the rotor inner flow passage 34 is a shape having corners such as a rectangle when viewed in the axial direction, the concentration of stress on a part of the inner side surface of the rotor inner flow passage 34 can be suppressed. Therefore, when the rotor 10 rotates around the central axis J, the in-rotor flow path 34 can be prevented from being deformed by centrifugal force or the like applied to the rotor core 30. Therefore, the flow rate of the refrigerant O flowing through the rotor inner flow path 34 can be stabilized. Therefore, the heat of the rotor core 30 and the plurality of magnets 40 can be stably released via the refrigerant O, and therefore, the temperature rise of the plurality of magnets 40 can be suppressed. The rotor inner flow path 34 may have another shape such as a circular shape when viewed in the axial direction. In addition, since stress concentration on a part of the inner surface of the rotor inner flow path 34 can be suppressed, occurrence of cracks or the like in the rotor inner flow path 34 can be suppressed.

As described above, the rotor inner passage 34 is surrounded by the single first magnet 41 and the pair of second magnets 43 and 44. As shown in fig. 4, the shortest distance L1 between the rotor inner flow path 34 and the first magnet 41 is a distance between a radially inward facing surface of the inner side surfaces of the rotor inner flow path 34 and the second outer side surface 41b of the first magnet 41, as viewed in the axial direction. The shortest distance L3 between the rotor inner flow path 34 and the second magnet 43 is a distance between an arc-shaped portion located on one side (+θ side) of the circumferential direction of the inner side surface of the rotor inner flow path 34 and the second outer side surface 43b of the second magnet 43, as viewed in the axial direction. The shortest distance L4 between the rotor inner flow path 34 and the second magnet 44 is a distance between the second outer side surface 44b of the second magnet 44 and an arc-shaped portion located on the other side (- θ side) in the circumferential direction of the inner side surface of the rotor inner flow path 34, as viewed in the axial direction. The shortest distance L3 between the rotor inner flow path 34 and the second magnet 43 and the shortest distance L4 between the rotor inner flow path 34 and the second magnet 44 are the same length as viewed in the axial direction. The shortest distance L1 between the rotor inner flow path 34 and the first magnet 41 is shorter than the shortest distances L3, L4 between the rotor inner flow path 34 and the second magnets 43, 44 as viewed in the axial direction.

The plurality of rotor hole portions 35 are holes penetrating the rotor core 30 in the axial direction. The plurality of rotor hole portions 35 may be holes having bottoms in the axial direction. As shown in fig. 2, the plurality of rotor hole portions 35 are provided at equal intervals over the entire circumference in the circumferential direction. In the present embodiment, the rotor hole portion 35 is provided with eight. As shown in fig. 3, the rotor hole portion 35 is provided at a position overlapping with an imaginary line Lq extending in the radial direction through the circumferential centers between the magnet holding portions 31 adjacent to each other in the circumferential direction, as viewed in the axial direction. The rotor hole portion 35 has a substantially triangular shape with rounded corners protruding radially outward as viewed in the axial direction. By providing the rotor core 30 with a plurality of rotor hole portions 35, the rotor core 30 can be reduced in weight. In the present embodiment, the virtual line Lq passes through the q-axis of the rotor 10 as viewed in the axial direction. The direction in which the virtual line Lq extends is the q-axis direction of the rotor 10.

The low thermal conductive layer 80 suppresses heat transfer from the rotor core 30 to the magnet 40. The low thermal conductive layer 80 extends in the axial direction. Although not shown, in the present embodiment, the low thermal conductive layer 80 is provided from the left end (+y side) to the right end (-Y side) of the magnet 40. The low thermal conductive layers 80 are respectively accommodated in the plurality of magnet holes 50. The low thermal conductivity layer 80 includes low thermal conductivity layers 81, 83, 84.

As shown in fig. 4, the low thermal conductive layer 81 is provided between the first outer side surface 41a and the first inner side surface 51e of the first magnet 41 in the first magnet hole 51. The low thermal conductive layer 83 is provided between the first outer side surface 43a and the first inner side surface 53e of the second magnet 43 in the second magnet hole 53. The low thermal conductive layer 84 is disposed between the first outer side 44a and the first inner side 54e of the second magnet 44 in the second magnet hole 54. That is, the low thermal conductive layer 80 is provided between the first outer surfaces 41a, 43a, 44a of the plurality of magnets 40 and the rotor core 30.

In the present embodiment, the low thermal conductive layers 81, 83, 84 are sheet-like members. The low thermal conductive layers 81, 83, and 84 are inserted into the magnet holes 50 together with the magnets 40 in a state of being attached to the first outer surfaces 41a, 43a, and 44a of the magnets 40. Although not shown in the drawings, in the present embodiment, the sheet-like low thermal conductive layers 81, 83, 84 are each substantially rectangular extending in the axial direction as viewed in the thickness direction of the low thermal conductive layers 81, 83, 84. The low thermal conductive layers 81, 83, 84 disposed in the respective magnet holes 50 expand in volume by heating and foaming, and cure in the expanded state. The low thermal conductivity layer 80 has a thermal conductivity smaller than that of the rotor core 30.

The low thermal conductive layer 81 presses the first magnet 41 against the second inner side surface 51f of the first magnet hole 51. The low thermal conductive layer 83 presses the second magnet 43 against the second inner side surface 53f of the second magnet hole 53. The low thermal conductivity layer 84 presses the second magnet 44 against the second inner side 54f of the second magnet hole 54. Thereby, each magnet 40 is fixed in each magnet hole 50. In addition, the second outer surfaces 41b, 43b, 44b of the magnets 40 are thereby brought into contact with the rotor core 30.

In the present embodiment, the low thermal conductive layers 81, 83, 84 include, for example, a thermosetting resin and a foaming agent that can be foamed by heating. The foaming agent contained in the low thermal conductive layers 81, 83, 84 is preferably a foaming agent that foams at a temperature lower than the curing temperature of the thermosetting resin to reach a maximum expansion state, for example. In this way, the thermosetting resin starts to cure after the foaming of the foaming agent is completed during the temperature rise at the time of heating of the rotor 10, and thus the low thermal conductive layers 81, 83, 84 expand stably. Therefore, the plurality of magnets 40 can be pressed against the second inner surfaces 51f, 53f, 54f of the plurality of magnet holes 50 by the low thermal conductive layers 81, 83, 84, respectively, and the plurality of magnets 40 can be stably fixed to the magnet holes 50, respectively.

Although not shown, adhesive layers are provided on the front and rear surfaces of the low thermal conductive layers 81, 83, and 84 of the present embodiment, respectively. Accordingly, the magnets 40 can be adhesively fixed to the magnet holes 50 via the low thermal conductive layers 81, 83, and 84. The low thermal conductive layers 81, 83, and 84 can be stably in contact with the first outer surfaces 41a, 43a, and 44a of the plurality of magnets 40 and the rotor core 30. The low thermal conductive layers 81, 83, 84 may be provided with an adhesive layer on only one of the front surface and the back surface. That is, the low thermal conductive layers 81, 83, 84 may be bonded and fixed to only one of the magnets 40 and the magnet holes 50. In addition, the adhesive layer may not be provided on the low thermal conductive layers 81, 83, 84.

The refrigerant flow path 90 is a path for supplying the refrigerant O stored in the gear housing 63b to the rotor 10 and the stator 61. As shown in fig. 1, a pump 97 and a cooler 98 are provided in the refrigerant flow path 90. The refrigerant flow path 90 includes a first flow path portion 91, a second flow path portion 92, a third flow path portion 93, a fourth flow path portion 94, a fifth flow path portion 95, an axial flow path 96, and the rotor inner flow path 34.

The first flow path portion 91, the second flow path portion 92, and the third flow path portion 93 are provided in, for example, a wall portion of the gear housing 63 b. The first flow path 91 connects a lower region of the gear housing 63b where the refrigerant O is stored to the pump 97. The second flow path 92 connects the pump 97 and the cooler 98. The third flow path portion 93 connects the cooler 98 and the fourth flow path portion 94.

The fourth flow path portion 94 is a tube extending in the axial direction. The fourth flow path portion 94 is supported at both axial ends by the motor housing 63 a. The fourth flow path portion 94 is disposed above the stator 61. The fourth flow path portion 94 has a plurality of supply ports 94a. The supply port 94a is a hole penetrating the fourth flow path portion 94 in the radial direction. In the present embodiment, the supply port 94a is an injection port that injects a part of the refrigerant O flowing into the fourth flow path portion 94 to the outside of the fourth flow path portion 94. The fifth flow path portion 95 is provided in the cover portion 63e. The fifth flow path portion 95 connects the fourth flow path portion 94 and the axial flow path 96.

The in-shaft flow path 96 is constituted by the inner surface of the hollow shaft 20. The in-shaft flow path 96 extends in the axial direction. The left end (+y side) of the in-shaft flow path 96 is located inside the gear housing 63b and opens to the left. As described above, the rotor inner flow path 34 is a hole penetrating the rotor core 30 in the axial direction. The axial center portion of the rotor inner flow passage 34 is connected to the plurality of holes 20 a. The rotor inner passage 34 is connected to the shaft inner passage 96 via a plurality of holes 20 a.

When the pump 97 is driven, the refrigerant O stored in the lower region in the gear housing 63b is sucked up by the pump 97 through the first flow path portion 91, and flows into the cooler 98 through the second flow path portion 92. The refrigerant O flowing into the cooler 98 is cooled in the cooler 98, passes through the third flow path portion 93, and flows into the fourth flow path portion 94. A part of the refrigerant O flowing into the fourth flow path portion 94 is injected from the supply port 94a and supplied to the stator 61. Another part of the refrigerant O flowing into the fourth flow path portion 94 passes through the fifth flow path portion 95 and flows into the axial flow path 96.

Part of the refrigerant O flowing into the in-shaft flow path 96 flows into the in-rotor flow path 34 through the plurality of holes 20a. Another part of the refrigerant O flowing through the in-shaft flow path 96 flows from the left side (+y side) opening of the shaft 20 into the gear housing 63b, and is again accumulated in the lower region in the gear housing 63 b.

The refrigerant O flowing into the rotor inner flow path 34 flows in the rotor inner flow path 34 to the left side (+y side) and the right side (-Y side). The refrigerant O flowing through the rotor inner flow path 34 contacts the inner surface of the rotor inner flow path 34, and absorbs heat of the rotor core 30 and heat of the plurality of magnets 40. Accordingly, the heat of the rotor core 30 and the heat of the plurality of magnets 40 are released to the refrigerant O, and the rotor core 30 and the plurality of magnets 40 are cooled. The refrigerant O flowing through the rotor inner flow path 34 is scattered radially outward from both axial ends of the rotor core 30, and supplied to the stator 61.

The refrigerant O supplied to the stator 61 from the supply port 94a of the fourth flow path portion 94 and the axial ends of the rotor inner flow path 34 cools the stator 61 by absorbing heat of the stator 61. In more detail, the refrigerant O is supplied to the coil 61c, absorbing heat of the coil 61c and heat of the stator core 61 a. The refrigerant O supplied to the stator 61 falls downward and is accumulated in a lower region in the motor case 63 a. The refrigerant O accumulated in the lower region in the motor housing 63a returns into the gear housing 63b through the partition wall opening 63 f.

In the rotor 10 of the present embodiment, the closer the portion located radially outward is to the stator 61, the more magnetic flux flowing between the rotor 10 and the stator 61 passes through. Therefore, the magnetic flux passing through the first magnet 41 disposed radially outward of the second magnets 43, 44 is larger than the magnetic flux passing through the second magnets 43, 44. Therefore, when the rotor 10 rotates around the center axis J during driving of the driving device 1, the amount of change in magnetic flux passing through the first magnet 41 is larger than the amount of change in magnetic flux passing through the second magnets 43, 44, and thus the eddy current generated in the first magnet 41 is larger than the eddy current generated in the second magnets 43, 44. Therefore, in the conventional structure, the heat of the joule heat generated by the first magnet 41 is larger than the heat of the joule heat generated by the second magnets 43, 44.

In addition, when the drive device 1 is driven, heat of the stator 61 is transmitted to the outer peripheral surface of the rotor core 30 via the gap between the stator core 61a and the rotor core 30, and radiant heat is generated by radiation from the stator core 61a, so that the temperature of the outer peripheral surface of the rotor core 30 rises. Since the distance between the first magnet 41 disposed radially outward of the second magnets 43, 44 and the outer peripheral surface of the rotor core 30 is short, heat of the stator core 61a is easily transferred. The temperature is more likely to rise than the second magnets 43 and 44. Thus, when driving the driving device 1, the first magnet 41 is more likely to have a higher temperature than the second magnets 43 and 44, and the first magnet is more likely to be demagnetized than the second magnets 43 and 44 due to the higher temperature.

In contrast, according to the present embodiment, in the rotor 10, the flow path 34, which is the rotor flow path, is surrounded by the plurality of magnets 40 when viewed in the axial direction, the plurality of magnets 40 include the first magnet 41 and the second magnets 43, 44, the first magnet 41 is disposed radially outward of the second magnets 43, 44, and the shortest distance L1 between the rotor flow path 34 and the first magnet 41 is shorter than the shortest distances L3, L4 between the rotor flow path 34 and the second magnets 43, 44 when viewed in the axial direction. Therefore, the first magnet 41 can be disposed close to the rotor inner flow path 34. This can increase the amount of heat released from the first magnet 41 to the refrigerant O flowing through the rotor core 30 in the rotor inner flow path 34, and can suppress the temperature rise of the first magnet 41. Therefore, as described above, even when a neodymium magnet containing no heavy rare earth having a temperature lower than that at which demagnetization occurs is used as the first magnet 41, demagnetization of the first magnet 41 can be suppressed. Accordingly, it is possible to suppress a decrease in output efficiency of the rotary electric machine 60 and the driving device 1, and to suppress an increase in manufacturing cost of the first magnet 41.

In the present embodiment, the second magnets 43 and 44 are disposed radially inward of the first magnet 41, so that the temperature rise is smaller than that of the first magnet 41. Therefore, even when a neodymium magnet containing no heavy rare earth is used as the second magnets 43, 44, demagnetization of the second magnets 43, 44 can be suppressed. Accordingly, it is possible to suppress a decrease in output efficiency of the rotary electric machine 60 and the driving device 1, and to suppress an increase in manufacturing cost of the second magnets 43, 44.

In the present embodiment, since the rotor inner passage 34 is surrounded by the plurality of magnets 40, it is easy to dispose each of the magnets 40 close to the rotor inner passage 34. Therefore, the heat released from each magnet 40 to the refrigerant O can be increased, and thus the temperature rise of each magnet 40 can be more appropriately suppressed.

According to the present embodiment, the plurality of magnetic pole portions 10P each include the first magnet 41 and the pair of second magnets 43, 44, and the pair of second magnets 43, 44 extend in a direction that is circumferentially separated from each other as seen in the axial direction from the radially inner side toward the radially outer side, and the rotor inner flow passage 34 is arranged between the pair of second magnets 43, 44 in the circumferential direction. Accordingly, the second outer surfaces 43b and 44b of the pair of second magnets 43 and 44 can be arranged so as to face the rotor inner passage 34 in the circumferential direction. Therefore, the longest distance between the rotor inner passage 34 and the second outer surfaces 43b, 44b can be shortened, and therefore, the variation in the heat dissipation amounts of the second magnets 43, 44 can be suppressed in the radial direction, and the temperature of a part of the second magnets 43, 44 can be suppressed from becoming excessively high.

In the present embodiment, since the rotor flow path 34 is arranged between the pair of second magnets 43 and 44 in the circumferential direction as described above, the plurality of magnets 40 are easily arranged so as to surround the rotor flow path 34. Accordingly, the magnets 40 are easily disposed close to the rotor inner flow path 34, and therefore, the heat released from the magnets 40 to the refrigerant O is easily increased. Therefore, the temperature rise of each magnet 40 can be more appropriately suppressed.

According to the present embodiment, each of the plurality of magnetic pole portions 10P has one first magnet 41, and the first magnet 41 extends in a direction orthogonal to a magnetic pole virtual line Ld passing through the center of the circumferential direction of the magnetic pole portion 10P and extending in the radial direction, as viewed in the axial direction. Therefore, compared to the case where the first magnet 41 extends in a direction inclined from the direction orthogonal to the magnetic pole virtual line Ld, the magnetic flux passing through the first magnet 41 is more likely to increase, and therefore, the heat of joule heat generated by the first magnet 41 is more likely to be larger than the heat of joule heat generated by the second magnets 43, 44, as viewed in the axial direction. In contrast, in the present embodiment, since the first magnet 41 can be disposed close to the rotor inner flow path 34 as described above, the amount of heat released from the first magnet 41 to the refrigerant O flowing through the rotor core 30 in the rotor inner flow path 34 can be increased, and the temperature rise of the first magnet 41 can be suppressed. Therefore, demagnetization of the first magnet 41 can be suppressed more appropriately, and therefore, a decrease in output efficiency of the rotating electric machine 60 and the driving device 1 can be suppressed more appropriately, and an increase in manufacturing cost of the first magnet 41 can be suppressed.

In the present embodiment, the longest distance between the second outer surface 41b of the first magnet 41 and the rotor inner passage 34 can be shortened as compared with a case where the first magnet 41 extends in a direction inclined from the direction orthogonal to the magnetic pole virtual line Ld when viewed in the axial direction. Therefore, the variation in the heat radiation amount of the first magnet 41 can be suppressed in the circumferential direction, and therefore, the temperature of a part of the first magnet 41 can be suppressed from becoming excessively high.

According to the present embodiment, the first magnet 41 and the rotor inner flow path 34 are disposed at positions overlapping the magnetic pole virtual line Ld, respectively, when viewed in the axial direction, and the rotor inner flow path 34 extends in a direction orthogonal to the magnetic pole virtual line Ld. Therefore, the direction in which the second outer surface 41b of the outer surface of the first magnet 41 facing the rotor inner flow path 34 extends can be the same as the direction in which the surface of the inner surface of the rotor inner flow path 34 facing the radial inner side extends, as viewed in the axial direction, and therefore the longest distance between the second outer surface 41b of the first magnet 41 and the rotor inner flow path 34 can be shortened. Therefore, the variation in the heat radiation amount of the first magnet 41 can be more appropriately suppressed in the direction in which the first magnet 41 extends, and therefore, the temperature rise of a part of the first magnet 41 can be more appropriately suppressed.

In the present embodiment, since the rotor flow path 34 extends in the direction perpendicular to the magnetic pole virtual line Ld as described above, the area of the surface of the rotor flow path 34 facing the radial direction inside can be increased. When the rotor 10 rotates around the central axis J, the refrigerant O flowing through the rotor inner flow path 34 is easily caused to flow in the axial direction along the radially inner surface of the rotor inner flow path 34 due to the centrifugal force applied to the refrigerant O. This can increase the contact area between the refrigerant O flowing through the rotor inner flow path 34 and the radially inward surface of the rotor inner flow path 34. Therefore, the heat of the first magnet 41 released to the refrigerant O flowing through the rotor inner flow path 34 can be more appropriately increased, and therefore, the temperature rise of the first magnet 41 can be more appropriately suppressed.

According to the present embodiment, the low thermal conductivity layer 80 is provided between the rotor core 30 and the first outer surfaces 41a, 43a, 44a of the plurality of magnets 40 facing the opposite side of the rotor inner flow path 34, and the second outer surfaces 41b, 43b, 44b of the plurality of magnets 40 facing the rotor inner flow path 34 contact the rotor core 30, and the thermal conductivity of the low thermal conductivity layer 80 is smaller than the thermal conductivity of the rotor core 30. Therefore, compared to the case where the first outer side surface 41a of the first magnet 41 facing radially outward directly contacts the rotor core 30, the thermal resistance between the first outer side surface 41a and the rotor core 30 can be increased. Therefore, the heat transferred from the stator 61 to the first outer surface 41a via the rotor core 30 can be more appropriately suppressed, and therefore, the temperature rise of the first magnet 41 can be more appropriately suppressed.

In the present embodiment, the thermal resistance between the first outer surfaces 41a, 43a, 44a of the plurality of magnets 40 and the rotor core 30 can be made larger than the thermal resistance between the second outer surfaces 41b, 43b, 44b of the plurality of magnets 40 and the rotor core 30. Therefore, the heat amounts T12, T32, T42 emitted from the second outer surfaces 41b, 43b, 44b of the magnets 40 toward the rotor inner flow path 34 can be made relatively larger than the heat amounts T11, T31, T41 flowing into the first outer surfaces 41a, 43a, 44a of the magnets 40 from the opposite side to the rotor inner flow path 34. Therefore, the temperature rise of each magnet 40 can be more appropriately suppressed.

< Modification of the first embodiment >

Fig. 5 is a cross-sectional view showing a part of a rotor 110 of a driving device 101 according to a modification of the first embodiment. In the following description, the same reference numerals are given to the same components as those of the first embodiment, and the description thereof will be omitted.

The rotor flow path 134 provided in the magnet holding portion 131 of each of the plurality of magnetic pole portions 110P of the present modification is elliptical in shape with a major axis extending in a direction orthogonal to the magnetic pole virtual line Ld, as viewed in the axial direction. Therefore, according to the present embodiment, the shortest distance L1 between the first magnet 41 and the portion on the circumferential center side of the rotor inner flow path 134 can be shortened, and the shortest distance between the first magnet holes 51 and the portion on the circumferential both sides of the rotor inner flow path 134 can be suppressed from becoming too short. Therefore, the heat released from the first magnet 41 to the refrigerant O flowing through the rotor core 130 can be increased, and therefore, the temperature rise of the first magnet 41 can be suppressed, and the wall thickness of the rotor core 130 between the portions on both sides in the circumferential direction of the rotor core 134 and the first magnet holes 51 can be suppressed from becoming too thin, and therefore, the rigidity of the portion surrounded by the plurality of magnets 40 in the rotor core 130 can be suppressed from decreasing.

The rotor inner flow path 134 is provided at a position overlapping the magnetic pole virtual line Ld as viewed in the axial direction. In the present modification, the magnetic pole virtual line Ld passes through the center in the circumferential direction of the rotor inner flow path 134. The shape of the both ends in the circumferential direction of the rotor inner flow path 134 is a curve protruding outward in the circumferential direction, as viewed in the axial direction. Therefore, according to the present modification, as in the case of the rotor inner flow passage 34 of the first embodiment described above, stress concentration on a part of the inner side surface of the rotor inner flow passage 134 can be suppressed. Therefore, when the rotor 110 rotates around the central axis J, the deformation of the rotor inner flow path 134 due to the centrifugal force applied to the rotor core 130 or the like can be suppressed, and therefore the flow rate of the refrigerant O flowing through the rotor inner flow path 134 can be stabilized. Therefore, the heat of the rotor core 130 and the plurality of magnets 40 can be stably released via the refrigerant O, and therefore, the temperature rise of the plurality of magnets 40 can be suppressed.

The rotor flow path 134 is disposed radially inward of the first virtual line Lc1 and the second virtual line Lc2 as viewed in the axial direction. Therefore, according to the present modification, as in the first embodiment described above, the shortest distance between the rotor inner passage 134 and each of the first magnet hole 51 and the second magnet holes 53 and 54 can be suppressed from becoming too short. Therefore, the rigidity of the portion surrounded by the plurality of magnets 40 in the rotor core 130 can be suppressed from decreasing.

The rotor inner passage 134 is surrounded by one first magnet 41 and a pair of second magnets 43 and 44. The shortest distance L1 between the rotor inner flow path 134 and the first magnet 41 is shorter than the shortest distances L3, L4 between the rotor inner flow path 134 and the second magnets 43, 44 as viewed in the axial direction. Therefore, according to the present modification, the first magnet 41 can be disposed close to the rotor inner passage 134, so that the amount of heat released from the first magnet 41 to the refrigerant O can be increased. Therefore, the temperature rise of the first magnet 41 can be more appropriately suppressed.

< Second embodiment >

Fig. 6 is a cross-sectional view showing a part of a rotor 210 of a driving device 201 of the second embodiment. In the following description, the same reference numerals are given to the same components as those of the first embodiment, and the description thereof will be omitted.

The rotor 210 of the rotating electric machine 260 of the present embodiment includes the shaft 20, the rotor core 230, the plurality of magnets 240, and the low thermal conductive layer 280. The rotor core 230 includes a plurality of magnet holding portions 231 and a plurality of rotor inner passages 234.

In the present embodiment, one rotor passage 234 and four magnet holes 250 are provided in the plurality of magnet holding portions 231. In the present embodiment, the plurality of magnet holes 250 include first magnet holes 251 and 252 and a pair of second magnet holes 53 and 54 provided radially inward of the first magnet holes 251 and 252. The structures and the like of the second magnet holes 53, 54 of the present embodiment are the same as those of the second magnet holes 53, 54 of the first embodiment described above.

In the present embodiment, the plurality of magnets 240 includes: a pair of first magnets 241, 242 respectively accommodated in the pair of first magnet holes 251, 252; and a pair of second magnets 43, 44 respectively accommodated in the pair of second magnet holes 53, 54. The configuration and the like of the second magnets 43, 44 of the present embodiment are the same as those of the second magnets 43, 44 of the first embodiment described above.

In the present embodiment, each of the plurality of magnetic pole portions 210P is composed of one magnet holding portion 231 and a plurality of magnets 240 accommodated in the magnet holes 250 provided in the one magnet holding portion 231. The plurality of magnetic pole portions 210P have a pair of first magnet holes 251 and 252, a pair of second magnet holes 53 and 54, a pair of first magnets 241 and 242, and a pair of second magnets 43 and 44, respectively. Other structures of the plurality of magnetic pole portions 210P are the same as those of the plurality of magnetic pole portions 10P of the first embodiment described above.

In each of the magnetic pole portions 210P, the first magnet hole 251 and the first magnet hole 252 are arranged across the magnetic pole virtual line Ld in the circumferential direction. The magnetic pole virtual line Ld passes through the center of the pair of first magnet holes 251, 252 in the circumferential direction between them. The first magnet hole 251 is disposed on the circumferential side (+θ side) from the magnetic pole virtual line Ld. The first magnet hole 252 is disposed on the other side (- θ side) in the circumferential direction from the magnetic pole virtual line Ld. The pair of first magnet holes 251, 252 are arranged between the pair of second magnet holes 53, 54 in the circumferential direction. The pair of first magnet holes 251, 252 extend in a direction away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side. The pair of first magnet holes 251, 252 are arranged in a V-shape that expands in the circumferential direction as seen in the axial direction as going radially outward. The first magnet hole 251 and the first magnet hole 252 are formed in a symmetrical shape with respect to the magnetic pole virtual line Ld as a symmetry axis as viewed in the axial direction.

The first magnet hole 251 has a magnet receiving hole portion 251a, an inner hole portion 251b, and an outer hole portion 251c. The magnet accommodating hole 251a is rectangular with a long side in the direction in which the first magnet hole 251 extends, as viewed in the axial direction. The magnet accommodating hole 251a is disposed radially outward of the rotor inner flow path 234. The magnet housing hole 251a has a first inner side surface 251e and a second inner side surface 251f. The first inner side surface 251e is a surface facing the rotor inner flow path 234 side of the inner side surface of the magnet accommodating hole 251 a. The second inner side surface 251f is a surface facing the opposite side to the rotor inner flow path 234 side, of the inner side surfaces of the magnet accommodating hole 251 a. The inner hole 251b is connected to an end of the magnet accommodating hole 251a on the inner side in the radial direction. The outer hole 251c is connected to an end of the magnet accommodating hole 251a on the outer side in the radial direction. The inner hole 251b and the outer hole 251c constitute a magnetic flux shielding portion.

The first magnet hole 252 has a magnet receiving hole portion 252a, an inner hole portion 252b, and an outer hole portion 252c. The magnet housing hole 252a is rectangular in shape with a long side in the direction in which the first magnet hole 252 extends, as viewed in the axial direction. The magnet housing hole 252a is disposed radially outward of the rotor inner flow path 234. The magnet housing hole 252a has a first inner side surface 252e and a second inner side surface 252f. The first inner side surface 252e is a surface facing the rotor inner flow path 234 side of the inner side surface of the magnet accommodating hole 252 a. The second inner side surface 252f is a surface facing the opposite side of the rotor inner flow path 234 side from the inner side surface of the magnet accommodating hole 252 a. The inner hole 252b is connected to a radially inner end of the magnet accommodating hole 252 a. The outer hole 252c is connected to an end of the magnet housing hole 252a on the outer side in the radial direction. The inner hole 252b and the outer hole 252c constitute a magnetic flux shielding portion. Other structures and the like of the first magnet holes 251 and 252 are the same as those of the first magnet hole 51 of the above embodiment.

The pair of first magnets 241, 242 extend in a direction away from each other in the circumferential direction as seen in the axial direction from the radially inner side toward the radially outer side. The pair of first magnets 241, 242 are arranged in a V-shape that expands in the circumferential direction as they go radially outward, as viewed in the axial direction. The magnetic pole virtual line Ld passes between the pair of first magnets 241, 242. The first magnet 241 and the first magnet 242 are formed in a symmetrical shape with respect to the magnetic pole virtual line Ld as a symmetry axis as viewed in the axial direction. The first magnet 241 is disposed in the magnet accommodating hole 251 a. The first magnet 242 is disposed in the magnet accommodating hole 252 a. The first magnets 241 and 242 are disposed radially outward of the rotor inner flow path 234. As a result, the rotor inner flow path 234 is surrounded by the plurality of magnets 240 as viewed in the axial direction.

The first magnet 241 has a first outer side surface 241a and a second outer side surface 241b. The first outer side surface 241a is a surface facing the opposite side from the rotor inner flow path 234 side, of the outer side surfaces of the first magnets 241. The first outer side surface 241a faces radially outward. The first outer side surface 241a faces the first inner side surface 251e of the first magnet hole 251. The second outer surface 241b is a surface facing the rotor inner flow path 234 side of the outer surfaces of the first magnets 241. The second outer side surface 241b faces radially inward. The second outer side surface 241b is opposite to the second inner side surface 251 f.

The first magnet 242 has a first outer side 242a and a second outer side 242b. The first outer side surface 242a is a surface facing the opposite side from the rotor inner flow path 234 side, of the outer side surfaces of the first magnets 242. The first outer side surface 242a faces radially outward. The first outer side 242a faces the first inner side 252e of the first magnet hole 252. The second outer surface 242b is a surface facing the rotor inner flow path 234 side of the outer surfaces of the first magnets 242. The second outer side 242b is opposite the second inner side 252 f. The second outer side 242b faces radially inward. Other structures and the like of the first magnets 241 and 242 are the same as those of the first magnet 41 of the above embodiment.

The low thermal conductive layers 280 are respectively accommodated in the plurality of magnet holes 250. The low thermal conductivity layer 280 includes low thermal conductivity layers 281, 282, 83, 84. The structures and the like of the low thermal conductive layers 83, 84 of the present embodiment are the same as those of the low thermal conductive layers 83, 84 of the first embodiment described above.

The low thermal conductive layer 281 is provided between the first outer side surface 241a and the first inner side surface 251e in the first magnet hole 251. The low thermal conductive layer 282 is disposed between the first outer side 242a and the first inner side 252e in the first magnet hole 252. That is, the low thermal conductive layer 281 is provided between the first outer side surfaces 241a and 242a of the first magnets 241 and 242 and the rotor core 230. The low thermal conductivity layers 281, 282 have a thermal conductivity smaller than that of the rotor core 230.

The low thermal conductive layer 281 presses the first magnet 241 against the second inner side 251f. The low thermal conductive layer 282 presses the first magnet 242 against the second inner side surface 252f. Thereby, the first magnets 241, 242 are fixed in the first magnet holes 251, 252, respectively. In addition, the second outer surfaces 241b and 242b of the first magnets 241 and 242 are thereby brought into contact with the rotor core 230. Other structures and the like of the low thermal conductive layers 281 and 282 are the same as those of the low thermal conductive layer 81 of the above embodiment.

The rotor flow path 234 is disposed radially inward of the pair of first magnets 241, 242. The rotor inner flow path 234 is disposed between the pair of second magnets 43, 44 in the circumferential direction. The rotor inner channel 234 is surrounded by a pair of first magnets 241, 242 and a pair of second magnets 43, 44. The rotor flow path 234 is disposed radially inward of the first virtual line Lc1 and the second virtual line Lc2 as viewed in the axial direction. Therefore, according to the present embodiment, the shortest distance between the rotor inner channel 234 and each of the first magnet holes 251 and 252 and the second magnet holes 53 and 54 can be suppressed from becoming too short. Accordingly, the thickness of the rotor core 230 between the rotor inner flow passage 234 and each of the first magnet holes 251, 252 and the second magnet holes 53, 54 can be suppressed from becoming too thin, and therefore, the rigidity of the portion of the rotor core 230 surrounded by the plurality of magnets 240 can be suppressed from decreasing.

The rotor flow path 234 is provided at a position overlapping the magnetic pole virtual line Ld as viewed in the axial direction. The magnetic pole virtual line Ld passes through the center of the rotor inner flow path 234 in the circumferential direction. The rotor inner flow path 234 includes a first flow path portion 234a and a second flow path portion 234b. The first channel portion 234a is a portion of the rotor inner channel 234 that is disposed on the circumferential side (+θ side) from the magnetic pole virtual line Ld. The first channel 234a is disposed radially inward of the first magnet 241. The second flow path 234b is a portion of the rotor inner flow path 234 that is disposed on the other side (- θ side) in the circumferential direction from the magnetic pole virtual line Ld. The second channel 234b is disposed radially inward of the first magnet 242. The first flow path portion 234a and the second flow path portion 234b extend in directions away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side. The first channel portion 234a extends in a direction in which the first magnet 241 extends. The second flow path 234b extends in the direction in which the first magnet 242 extends. The radially inner end of the first flow path 234a and the radially inner end of the second flow path 234b are connected to each other. In the present embodiment, the first channel portion 234a and the second channel portion 234b are formed in a symmetrical shape with respect to the magnetic pole virtual line Ld as the symmetry axis when viewed in the axial direction.

The end portion of the first flow path 234a on one circumferential side (+θ side) has an arc shape protruding toward one circumferential side when viewed in the axial direction, and the end portion of the second flow path 234b on the other circumferential side (- θ side) has an arc shape protruding toward the other circumferential side. That is, both ends of the rotor inner flow path 234 in the circumferential direction have an arc shape protruding outward in the circumferential direction. Therefore, according to the present embodiment, as in the case of the rotor inner flow passage 34 of the first embodiment described above, stress concentration on a part of the inner side surface of the rotor inner flow passage 234 can be suppressed. Therefore, when the rotor 210 rotates around the central axis J, the deformation of the rotor inner flow path 234 due to the centrifugal force applied to the rotor core 230 or the like can be suppressed, and therefore the flow rate of the refrigerant O flowing through the rotor inner flow path 234 can be stabilized.

As described above, the rotor passage 234 is surrounded by the pair of first magnets 241 and 242 and the pair of second magnets 43 and 44. The shortest distances L1, L2 between the rotor inner flow path 234 and the respective first magnets 241, 242 are shorter than the shortest distances L3, L4 between the rotor inner flow path 234 and the respective second magnets 43, 44, as viewed in the axial direction. Therefore, according to the present embodiment, the first magnets 241 and 242 can be disposed close to the rotor inner flow path 234, and therefore, the heat released from the first magnets 241 and 242 to the refrigerant O flowing through the rotor inner flow path 234 can be increased, and the temperature rise of the first magnets 241 and 242 can be suppressed. Therefore, even when a neodymium magnet containing no heavy rare earth is used as the first magnets 241, 242, demagnetization of the first magnets 241, 242 can be suppressed. Accordingly, it is possible to suppress a decrease in output efficiency of the rotating electric machine 260 and the driving device 201, and to suppress an increase in manufacturing cost of the first magnets 241, 242.

According to the present embodiment, the plurality of magnetic pole portions 210P each include a pair of first magnets 241, 242, and the pair of first magnets 241, 242 extend in a direction away from each other in the circumferential direction as seen in the axial direction from the radially inner side toward the radially outer side, and a magnetic pole virtual line Ld extending in the radial direction passing through the center of the circumferential direction of the magnetic pole portion 210P as seen in the axial direction passes between the pair of first magnets 241, 242. In each magnetic pole portion 210P, the magnetic flux flowing between the rotor 210 and the stator 61 passes more toward the portion on the circumferential center side of each magnetic pole portion 210P, that is, the portion closer to the magnetic pole virtual line Ld. Therefore, since the magnetic flux passing through the portions of the first magnets 241 and 242 closer to the magnetic pole virtual line Ld increases, the eddy current increases in the portions of the first magnets 241 and 242 closer to the magnetic pole virtual line Ld when the rotor 210 rotates around the central axis J, and the heat of joule heat increases. In contrast, in the present embodiment, the closer the first magnets 241, 242 are to the magnetic pole virtual line Ld, the farther the portions are located radially inward, and thus the longer the distance between the first magnets and the outer peripheral surface of the rotor core 230 is. Therefore, the heat transferred from the stator 61 to the first outer side surfaces 241a and 242a via the rotor core 230 can be reduced as the first magnets 241 and 242 are closer to the magnetic pole virtual line Ld. Therefore, compared to the case where the first magnets 241 and 242 extend in the direction perpendicular to the magnetic pole virtual line Ld, the temperature rise of the portions of the first magnets 241 and 242 near the magnetic pole virtual line Ld can be suppressed.

According to the present embodiment, the rotor flow path 234 is disposed at a position overlapping the magnetic pole virtual line Ld as viewed in the axial direction, and the rotor flow path 234 includes: a first channel portion 234a disposed radially inward of one first magnet 241 and extending in a direction in which the first magnet 241 extends; and a second channel 234b disposed radially inward of the other first magnet 242 and extending in the direction in which the first magnet 242 extends. As a result, the second outer surface 241b of the first magnet 241 and the radially inward surface of the first channel 234a can be arranged in parallel, and the second outer surface 242b of the first magnet 242 and the radially inward surface of the second channel 234b can be arranged in parallel, as viewed in the axial direction. Therefore, the longest distance between each of the first magnets 241 and 242 and the rotor inner channel 234 can be shortened. Accordingly, the variation in the heat radiation amounts of the first magnets 241 and 242 can be suppressed in the circumferential direction, and therefore, the temperature rise of a part of each of the first magnets 241 and 242 can be appropriately suppressed.

In the present embodiment, as described above, the low thermal conductive layers 281 and 282 are provided between the first outer side surfaces 241a and 242a of the pair of first magnets 241 and 242, which face radially outward, and the rotor core 230, and the second outer side surfaces 241b and 242b of the pair of first magnets 241 and 242, which face radially inward, are in direct contact with the rotor core 230. Therefore, the thermal resistance between the first outer side surfaces 241a, 242a and the rotor core 230 can be made larger than the thermal resistance between the second outer side surfaces 241b, 242b and the rotor core 230. Accordingly, the heat T12, T22 emitted from the second outer side surfaces 241b, 242b of the pair of first magnets 241, 242 to the rotor core 230 can be made relatively larger than the heat T11, T21 flowing from the rotor core 230 into the first outer side surfaces 241a, 242a of the pair of first magnets 241, 242. Therefore, the temperature rise of the first magnets 241, 242 can be more appropriately suppressed.

The present invention is not limited to the above-described embodiments, and other configurations and other methods may be adopted within the scope of the technical idea of the present invention. The rotor inner flow path may be arranged so as to be surrounded by a plurality of magnets when viewed in the axial direction, and may have any shape or any arrangement. For example, the rotor inner flow path may have a circular shape, a rectangular shape, or the like, as viewed in the axial direction. The type of the refrigerant supplied into the rotor inner flow path is not particularly limited. The method of supplying the refrigerant into the rotor inner flow path may be any method.

The number of the rotor internal flow passages provided in one magnet holding portion is not particularly limited as long as it is one or more. When a plurality of rotor-internal flow passages are provided in one magnet holding portion, the plurality of rotor-internal flow passages may be arranged at intervals in the radial direction or may be arranged at intervals in the circumferential direction. In addition, the rotor hole may not be provided.

The rotary electric machine to which the present invention is applied is not limited to the motor, but may be a generator. The use of the rotary electric machine is not particularly limited. The rotating electric machine may be mounted on a device other than the vehicle. The application of the driving device to which the present invention is applied is not particularly limited. The driving device may be mounted on the vehicle for a purpose other than the purpose of rotating the axle, or may be mounted on a device other than the vehicle. The posture of the rotary electric machine and the driving device at the time of use is not particularly limited. The central axis of the rotating electric machine may be inclined with respect to a horizontal direction orthogonal to the vertical direction, or may extend in the vertical direction.

While the embodiments of the present invention have been described above, the structures and combinations thereof in the embodiments are examples, and the structures may be added, omitted, substituted, and other modified without departing from the spirit of the present invention. The present invention is not limited to the embodiments.

Note that the present technology can employ the following configuration.

(1) A rotor rotatable about a central axis, comprising: a rotor core having a plurality of magnet holes and a flow path through which a refrigerant flows; and a plurality of magnets which are respectively accommodated in the plurality of magnet holes, wherein the plurality of magnet holes and the flow path extend in an axial direction, the flow path is surrounded by the plurality of magnets when viewed in the axial direction, the plurality of magnets include a first magnet and a second magnet, the plurality of magnet holes include a first magnet hole accommodating the first magnet and a second magnet hole accommodating the second magnet, the first magnet is arranged at a position radially outside the second magnet, and a shortest distance between the flow path and the first magnet is shorter than a shortest distance between the flow path and the second magnet when viewed in the axial direction.

(2) The rotor according to (1), comprising a plurality of magnetic pole portions arranged in a circumferential direction, wherein each of the plurality of magnetic pole portions includes the first magnet and a pair of the second magnets, the pair of the second magnets extend in a direction that is separated from each other in the circumferential direction as seen in the axial direction from a radially inner side toward a radially outer side, and the flow path is arranged between the pair of the second magnets in the circumferential direction.

(3) The rotor according to (2), wherein each of the plurality of magnetic pole portions has one of the first magnets extending in a direction orthogonal to a magnetic pole virtual line passing through a center of a circumferential direction of the magnetic pole portion and extending in a radial direction, as viewed in an axial direction.

(4) The rotor according to (2), wherein the plurality of magnetic pole portions each have a pair of the first magnets, the pair of the first magnets extending in a direction away from each other in the circumferential direction as seen in the axial direction from the radially inner side toward the radially outer side, and a magnetic pole virtual line extending in the radial direction passing through the circumferential center of the magnetic pole portion passing between the pair of the first magnets as seen in the axial direction.

(5) The rotor according to (3), wherein the first magnet and the flow path are arranged at positions overlapping the magnetic pole virtual line, respectively, as viewed in the axial direction, and the flow path extends in a direction orthogonal to the magnetic pole virtual line.

(6) The rotor according to (4), wherein the flow path is arranged at a position overlapping the magnetic pole virtual line as viewed in the axial direction, the magnetic pole virtual line passing between a pair of the first magnets as viewed in the axial direction, the flow path having: a first channel portion that is disposed radially inward of one of the first magnets and extends in a direction in which the one of the first magnets extends; and a second flow path portion that is disposed radially inward of the other first magnet and extends in a direction in which the other first magnet extends.

(7) The rotor according to any one of (1) to (6), wherein the shape of both ends in the circumferential direction of the flow path is an arc shape protruding outward in the circumferential direction, as viewed in the axial direction.

(8) The rotor according to (3) or (4), wherein the flow path has an elliptical shape in which a major axis extends in a direction orthogonal to the magnetic pole virtual line, as viewed in the axial direction.

(9) The rotor according to any one of (2) to (8), wherein the flow path is arranged radially inward of each of a first virtual line orthogonal to a direction in which one of the second magnets extends and passing through a center of one of the second magnets in the direction in which the other of the second magnets extends, and a second virtual line orthogonal to the direction in which the other of the second magnets extends and passing through a center of the other of the second magnets in the direction in which the other of the second magnets extends, as viewed in the axial direction.

(10) The rotor according to any one of (1) to (9), wherein a low thermal conductive layer is provided between a first outer side surface of each of the plurality of magnets facing a side opposite to the flow path side and the rotor core, and a second outer side surface of each of the plurality of magnets facing the flow path side is in contact with the rotor core, and a thermal conductivity of the low thermal conductive layer is smaller than a thermal conductivity of the rotor core.

(11) A rotating electrical machine is provided with: the rotor of any one of (1) to (10); and a stator disposed radially outward of the rotor.

(12) A driving device is provided with: the rotary electric machine according to (11); and a gear mechanism coupled to the rotor.

Symbol description

1. 101, 201 … Drive means; 10. 110, 210 … rotors; 10P, 110P, 210P … pole portions; 30. 130, 230 … rotor cores; 34. 134, 234 … rotor inner flow paths (flow paths); 40. 240 … magnets; 41. 241, 242 … first magnets; 41a, 43a, 44a, 241a, 242a … first outer side; 41b, 43b, 44b, 241b, 242b … second outer side; 43. 44 … second magnets; 50. 250 … magnet holes; 51. 251, 252 … first magnet holes; 53. 54 … second magnet holes; 60. 160, 260 … rotating electrical machines; 61 … stators; 70 … gear mechanism; 80. 280 … low thermal conductivity layers; 234a … first flow path portion; 234b … second flow path portion; j … central axis; lc1 … first imaginary line; lc2 … second notional line; ld … magnetic pole imaginary line; o … refrigerant.

Claims

1. A rotor rotatable about a central axis, comprising:

a rotor core having a plurality of magnet holes and a flow path through which a refrigerant flows; and

A plurality of magnets respectively accommodated in the plurality of magnet holes,

The plurality of magnet holes and the flow path extend in the axial direction,

The flow path is surrounded by a plurality of the magnets as viewed in the axial direction,

The plurality of magnets includes a first magnet and a second magnet,

The plurality of magnet holes includes a first magnet hole for receiving the first magnet and a second magnet hole for receiving the second magnet,

The first magnet is disposed radially outward of the second magnet,

The shortest distance between the flow path and the first magnet is shorter than the shortest distance between the flow path and the second magnet when viewed in the axial direction.

2. The rotor of claim 1, wherein the rotor comprises a plurality of rotor blades,

Comprises a plurality of magnetic pole parts arranged along the circumferential direction,

The plurality of magnetic pole portions each have the first magnet and a pair of the second magnets,

The pair of second magnets extend in a direction away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side,

In the circumferential direction, the flow path is arranged between a pair of the second magnets.

3. A rotor according to claim 2, wherein,

The plurality of magnetic pole portions each have one of the first magnets,

The first magnet extends in a direction orthogonal to a magnetic pole virtual line extending through a center of a circumferential direction of the magnetic pole portion and in a radial direction, as viewed in an axial direction.

4. A rotor according to claim 2, wherein,

The plurality of magnetic pole portions each have a pair of the first magnets,

The pair of first magnets extend in a direction away from each other in the circumferential direction as viewed in the axial direction from the radially inner side toward the radially outer side,

A magnetic pole imaginary line extending in the radial direction passing through the center of the circumferential direction of the magnetic pole portion passes between a pair of the first magnets as viewed in the axial direction.

5. A rotor according to claim 3, wherein,

The first magnet and the flow path are arranged at positions overlapping the virtual magnetic pole line, respectively, when viewed in the axial direction,

The flow path extends in a direction orthogonal to the magnetic pole virtual line.

6. The rotor as set forth in claim 4, wherein,

The flow path is arranged at a position overlapping with the magnetic pole virtual line when viewed in the axial direction,

Viewed in the axial direction, the magnetic pole imaginary line passes between a pair of the first magnets,

The flow path has: a first flow path portion that is disposed radially inward of one of the first magnets and extends in a direction in which the one of the first magnets extends; and a second flow path portion that is disposed radially inward of the other first magnet and extends in a direction in which the other first magnet extends.

7. The rotor according to any one of claim 1 to 6, wherein,

The shape of the two ends of the flow path in the circumferential direction is arc-shaped protruding outwards in the circumferential direction when seen along the axial direction.

8. A rotor according to claim 3 or 4, characterized in that,

The flow path is elliptical with a major axis extending in a direction perpendicular to the virtual magnetic pole line, as viewed in the axial direction.

9. The rotor according to claim 2 to 6, wherein,

The flow path is arranged radially inward of each of a first virtual line orthogonal to a direction in which one of the second magnets extends and passing through a center of one of the second magnets in the direction in which the other of the second magnets extends, and a second virtual line orthogonal to the direction in which the other of the second magnets extends and passing through a center of the other of the second magnets in the direction in which the other of the second magnets extends, as viewed in the axial direction.

10. The rotor according to any one of claim 1 to 6, wherein,

A low thermal conductive layer is provided between a first outer side surface of each of the plurality of magnets facing a side opposite to the flow path side and the rotor core,

A second outer side surface of each of the plurality of magnets facing the flow path side is in contact with the rotor core,

The low thermal conductivity layer has a thermal conductivity smaller than that of the rotor core.

11. An electric rotating machine, comprising:

The rotor of any one of claims 1 to 5; and

A stator disposed radially outward of the rotor.

12. A driving device is characterized by comprising:

the rotary electric machine of claim 11; and

And a gear mechanism connected with the rotor.